1. Field of the Invention
The present invention relates generally to tools and more particularly to a method and an apparatus for removing landing gear struts from aircrafts having retractable landing gear.
2. Description of the Related Art
Retractable aircraft landing gear struts periodically need to be removed for maintenance. One reason is that retractable landing gear systems typically include hydraulic assemblies that, over time, require servicing to maintain proper fluid and pressure levels.
Maintenance of the hydraulic landing gear assemblies is required only once every few years. Other than servicing the strut to maintain the hydraulic retractable landing gear system, the struts are not usually removed. Accordingly, some struts are not removed from their aircraft for many years. While the aircraft strut is left untouched for many years, most aircraft are occasionally and sometimes frequently exposed to damp or wet environmental conditions. Some aircraft are even usually left out in the weather most of the time. Accordingly, without proper maintenance, some aircraft parts collect moisture that often causes corrosion and its undesirable effects.
The problem is especially acute for some small and older aircraft having a specific type of retractable landing gear strut. For these aircraft, corrosion often causes the landing gear strut to become bonded or seized to a pivoting landing gear support. The pivoting landing gear support is the device in a landing gear system that receives and holds the landing gear strut into place. By design, only removable retaining bolts, pins or springs (collectively "pins") are used to hold a landing gear strut in place. With corrosion that commonly develops between the landing gear strut and the pivoting landing gear support, however, the retaining pins may not be solely responsible for holding the strut in place. Thus, the struts are very difficult to remove even after retaining bolts or pins are removed.
Whenever a landing gear strut becomes seized by corrosion and the strut must be removed for servicing, a challenge is presented for economically removing the strut without damaging it. Occasionally, extreme amounts of force are required to grip the strut and to break it free from the pivoting landing gear support. Sometimes, aircraft mechanics apply significant force to the strut for prolonged periods to try to break it free from the corrosive grip of the landing gear support.
Even if the mechanic is successful in removing the landing gear strut, a mechanic frequently spends as much as eight hours trying to remove the strut without damaging it or the aircraft. Moreover, given that aircraft repair labor rates can approach $100 per hour at the time of this application, the labor cost for merely removing a strut can exceed $800.
Damaging the strut or the airplane or its components is common for experienced aircraft repair mechanics while trying to remove a strut seized by corrosion. If the strut or aircraft is damaged as often happens, however, the cost of trying to remove the strut can exceed thousands of dollars in parts and labor. Consequentially, properly servicing an aircraft's landing gear assembly is unduly expensive.
Thus, there exists a need in the art for a tool that can quickly remove an aircraft strut, and in particular, a retractable aircraft landing gear strut for certain models having a pivoting landing gear support and mating strut that are subject to the aforementioned problems, without damaging either the strut or the airplane and without requiring significant levels of effort. In general, there is need for a tool and a method to economically remove the struts to facilitate and encourage proper maintenance of the aircraft landing gear systems.